Safety lathe dog



G. T. BURROWS.

SAFETY LATHE DOG.

UNITED STATES SAFETY LAT-HEDOG.

SpecicationioLetters Patent. Patgntgd Riad', 14; 1922;'

Application ledfAugust 9, 1920.-', Serial .'No. 402,423.`

Toh/ ill whome't may concern'.

VBe it known 'that I, GnoRGnf T. BURRowaz a citizen .of the United States, and a'residentof Cleveland, county of` Cuyahogay and State1 of Ohio, liave-inventeda new andfuseful Improvement.l in Safety Lathe Dogs, of which the following is a specification, the principley of the. invention being hereinex.-y

plainedand-the best inode iniwhich I have contemplated. applying that principle, .sof asY to distinguish itroni, otherf inventions.

The present4 inventionI relates'v to..v ai lather dog, .and more pp articul arly tol thev construe;

tion-thereof, whereby. a vsmooth exterior-is` closed Vmeans, constituting, however, but one ofvarious. mechanical ormsin which the principle ofthe invention. maybe used. In saidannexeddrafwingzf-r y Figi. 1 kis .a-f persp ectiveA view. ofjmy. im;y provedglatheedog.; Fig. 2 is.v an` elevational view ofthe .drivingside ofthedog withgthe.

cover. plate.removed;V and Fig.A 8, isV aseotionalr view on theline: 3 3 oflig. 2 but showing. the. cover platein, posi-tion;

The defviceconsists of a cylindrical heus: ing or spiderv l, whichis provided .witha centralhub V2, the housing-being closed,v at therear excepting: fonan, aperturef 3,. and being cut away. to; form a, series, ot varmsfor ribs 4in order, to lighten thehousing. On itsf outer v'suriiace and communicating with one. of. the recessesfG between the ari-11s the housing,isiprovidedwitha Slot, 7; Atione side. the housing is .left solid ,andjf'rom the hubaV squarefreoessS', iscut into thia solid portion, thisl recess AcommunicatifngpY with an aperture 9A extending; theE rest'. of( the way' through, the. housing., The housing is, also provided', adj aoenf its. forward face with` an annular; flange, l'Oformiiig, a, shouldenfll wtthe surface .ofthe lousnanmpen Oppositethe. square erecess, the housing is PATENT OFFICE; GEORGEy T. Bonnows; or omivmsrenon loran-,nenn ToL y l "GRoENKn-'or LIMA; omo. Y

provided with another solid portion having` rectangular recess or. slotk 12,.,wh1ch `1s also cutfthrough the,hub,.and this recess is aidaptedto receive a removable ,jaw-lvwhich. is: provided at' its: outer sijde with a, curved recess-.1i adapted to be in. alignment with: the. aperture B-.in the4 faceof the housing, A .tail 15 having an eccentric portion` 16, r is, adapted tot in the curved recess 14k .offthe andtohave a bearing,in .theaperture.

wwithin the housing.` This tail extends outt beyondthe. drivingfaee of the. housing andi rota=tivej-movement of the. sarnepis adapted, to. .ca1ri thejaw inwardly. so that'. itextends, slightly: bevondthe hub in .orden to. .ai d`ingrippingY ther stocln when .the lathefdog, is in operation.. In thev square recess, 8.5 opposite.. L the jaw, a standard square nut 2() isadaptet to. .be removably mounted andheldfin'y place by. 'a'. screw 2l, whichzisreceived .in atapped: aperture 122 extending throughthe hub., Re-

movably mountedthrouglithis An utgisa. setV .Y

screw 2.3.which extends outwardly` through the. ajperture.`v in communication` with;` the square recess but the` slet` screw isof-V suchg-a length thatitnorinally lies below. thebuter surface of the housing. This set. screw is adapted to. be. forced into :Contact Qwithl the stoelry and to ho ld itsecurelyfagainst thefjaw. Toenolosef the casing so as 'to leave.. a

smooth'` exterior with. the .exception Aofljtlhe Y extending tail, a. movable ring:y 25 is mounted 'over 'the.housin,q, the ring;v having two an'- nular flanges 26, `one ofY whichts against the Harige 10 on the. housing` soas toprevent the removal of` theA ring from the housing; 'in one direction, while-the other flange receives .'a-cover plate` 27 which'its iiush vwithin.the

ring. 'Ihe` cover plate is.v attacheditothe hnisi-ngbv` means offour screwsY which engage with tapped apertures vv2 9 v'inthe arms of thehousing@ V'I .hiscover platel-isprovidedl I with la central aperture 3Q ot Suf/ l .Simens to fit around jthe hub; of the housin-,sfnl and loni'ts inner surface, it: is providetfwitn alug- 3 1 fitting back .cette @nager-ineen., the, rug

asa .bearing ,therefor- The 'rlgLhaS limited pin 33' which. extends, through'thesltfinY the housing: into, one off the' reeessesg betweenlthe arms.. iThe snrngZjengagesgwith Y flush with. or slightly belovv the surface oi this pin and contacts with one of the arms to maintain the ring in its normal closed. position. T he ring is provided with a single aperture 33% having a rounded edge Set which aperture in one position oi the ring is adapted to he an alignment in the aperture in the housing which receives the set screw, so that a Wrench or other tool, may be inserted to tighten the set screw and torce the stockl The driving side of the dog is entirelycov` ered by the cover plate which carries 'Four screws for holding vthe plate in position, these screws as shown, being received lin countersunk apertures, so that the screvvs are the plate. Y I

As shown, each operative part ot' the dog is'easily removable'V and those parts'ivhich are liable to breakage, such as the jaw, tail,

- set screnT and nut, can be removed and replaced by merely taking off the cover plate` of the dog. The tail a flattened side which is adapted to engage with the aperture of the face plate ot the lathe in such a Way, that the driving of the latter tends 'to rotate the tail and thus the eccentric, to force the jaw inwardly against the stock. rlhus the more power it takes to drive the stoclr,

V the tighter the stock Will be held in the dog.

The removal nut and set screvv are standard articles which may be purchased trom any hardware store and while the i-avr and tail must bemade special, they are easily removable and can readily be supplied .if breakage should occur. lt will thus be clear that the housing is` so formed as to eliminate any-danger to the, operator and at the same time, the Working partsare readilyV available so that in case. of breakage. they canbe ref moved and Vnew parts substituted with a minimum of delay. Y Other modes of applying the principle of my inventionmay b e employediinsitea'd of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent oit such stated means be employed.` i y 'I therefore particularly point out and distinctlyy claim as my invention 1.- .y i

V1. ,In a lathe-dog, the combination oa cylindrical housing vprovidedvvitb a central aperture and tivo opposed recesses in communication therewith, a removable Jaw and operating tail mounted in one oif'such re cesscs, a removable set screw and nut mountedin the other o't' such recesses, a cover plate removably attached to one face et said housing and a cylindrical ring fitting over said housing and making a flush surface with said housing Vand plate.

2.V In a lathe-dog, the combination of a cylindrical housing having a central aperture, one tace being closed and the other tace being holloived out leaving a series of arms, two diametrically opposed recesses in such housing in communication With such central opening, a removable jaw movably mounted in one such recess, a tail also rotatably mounted in such recess and operatively con`- nected to said jaw to move the same uponrotation of `said tail about its ovvn axis, a set' screw andnut removably mountedV in the other rof such recesses, a cover plate for the open side of said housing, and a cyline drical ring adapted to t over said housing and to make a ush surface With said housing and said plate'. y Y y 3. In a lathe-dog, the combination ota cylindrical housing having a closed face and Y being hollovved .out to, leave a series of arms, and recesses, said housinghaving a central aperture and provided with a hub on `thev open side ofsaid housing,jone of said arms having a square recess cpeninginto lsaid hub and an aperture through said arm to the exterior Yof said housing, the arm opposite thereto having a rectangular recess, a nut removably mounted in ksuch square recess, .av set screw mounted in said nut and extending through such recess into suchy aperture, a'jaw and tail removably mountedl in ysaid rectanguiar' recess, said tail beingfrotatably mount'- ed Yand being operativelyY connected to said jaw to move the samepinvvardly upon rotation of said tail about said airis, a cover plateior such open side olf'said housing, and Y a ring having an aperture'movablymounted on said housing, said ringbeing normally held Iin closed position but'being adapted :to be moved to align such apertures in ring and housing, to permit access. to `said set screw.

4. In a lathe-dog, the combination'of a cylindrical housing having a closed face and being hollovved out toleave a' series'otarms and recesses, said` housing Vhaving a central aperture and provided VWith a" hub, on the open side of said housing, one of said arms having a square recess opening 'into said hub andan aperture through said arm tothe exe terior of said'housing, arm opposite ythereto havingy a rect-angular(recess,y a `nut j aw upon rotation of said tail about its own axis, a cover plate for such open side of said casing said plate having an aperture adapted to fit over said hub' andto form a Hush surface therewith, a ring movably mounted on said housing and provided With an aperture adapted to register in one position with the aperture in said housing to permit access to said set screw.

5; In a lathe-dog, the combination of a hollow cylindrical housing having one closed face, said housing having a central aperture and being provided with a hub and arms between said hub and the exterior surface, one of said arms being provided with a square recess opening into such central aperture, and a communicating aperture through the eXterior of said housing, a second arm opposite said rst and provided with a rectangular recess, a nut removably secured in such square recess, a set screw mounted onl said nut a removable apertured jaw mounted in said mounted in said rectangular recess andl in such apertured jaw and being provided With a cam face adapted to move said jaw upon rectangular. recess, a tail rotatably Y rotation of said tail about its own axis, a Y

ring mounted on said housing and having an L Signed by Vme this 4th day of August, 1920. r

' GEORGE T. BUR-ROWS.

Vitnesses: Y Y

D. C. PEABODY, Mrs. J. C. MANVILL'E. 

